Before the repairs, the dome had more than 1,300 "cracks and deficiencies" in its corroded cast iron structure, Architect of the Capitol Stephen T. Ayers said.

About 52 miles of pipe crisscrossed the 29-story dome with a thick layer of scaffolding for two years during the project, a frustrating eyesore for many tourists and D.C. residents. The scaffolding was removed as work was completed.

The unveiling of the repaired building comes just as President-elect Donald Trump prepares to be sworn into office. Last year, Trump said the project reflected what was wrong with Washington, calling the repair efforts wasteful and behind schedule. He said the scaffolding would be removed for the 2017 inauguration and put back up.

Instead, the project was finished on time, just before the inauguration ceremony.

"I am so proud of our team. They worked through the night and in all kinds of weather -- from snow storms to scorching hot summer days.... It is important to take a moment to celebrate and share the fine work done here," said Ayers.